To the rest of the world, the Marilanth Petal is a criminal organization, peddling drugs and poisons in alleyways the world over. But in Bospero, they are merely another of the noble clans--another miniscule dukedom in a city infested with dukes.
That the Duke of Poppies is the head of a criminal enterprise is no secret, but it is certainly not something that is remarked upon in polite company. Besides, the city already tolerates greater offenses against decency (the Stewer's Guild, the Black Rabbits, the ever-larger fashions of the nobility, the scandals of the Queen, and the financial predations of dragonkind) and is perhaps stronger for it.
A Sidebar: Bospero
The largest city in the world, Bospero is technically a tight cluster of dukedoms, each separated on a small island, where the duke holds absolute power. These islands are separated from each other by trash-filled canals, protected from the roughest vagaries of the sea by a maze of breakwaters, built atop Odo Longo, a sunken city just off the coast, thought to be build by giants in past ages.
These dukedoms were originally limited, and only awarded infrequently, but as the breakwaters proved too be too effective, silt built up around the city, and the ocean became shallow enough that islands could be constructed by ambitious nobles. And while the granting of duchies has ebbed and flowed with the options of the regent, the end result is that Bospero now has nearly a hundred soverign duchies, all locked together in a maze of shallow canals, each with the power to negotiate foreign treaties, tax visitors, and declare war on other duchies.
Bospero is a famously difficult to city to navigate. Foreigners describe the city as pure madness, a riotous warren of strange laws, toll bridges, mystery cults, incomprehensible dialects, and a heady gradient between street gangs and duchal armies. The locals are proud of their city and its reputation. They wouldn't have it any other way.
This is also where Coramont, the Holy City, is located.
End of Sidebar
Where was I? Oh yes, the Duke of Lornavel is a terrible man. If you ever wish to make a name for yourself in Bospero, make sure that you are a friend to him.
But there is a reason why the island of Lornavel is given this special dispensation: they are responsible for satisfying the Mantleray. They are not scrutinized by the queensguard; the Grand Euphorium is never searched. The crown doesn't even tax them--their only civic responsibilities are the deliveries.
The deliveries are more drugs, of course.
Vast amounts. Impossible amounts. Pools of poppy extract. Casks of delago. Enough tambrack to smother a child, or ten. Thrum, mevverwen, jopeth, scrumboola. Fat-petaled lotuses, big as a crown.
And for this delivery, they have only a single client, the Mantlewray.
More correctly, her name is Elzabeth Jonna Mantlewray, the former duchess of Madrigo. Her story is lost, another victim of her own predations, but pieces of her history can still be assembled from among the flotsam.
Most of the stories agree that she did it to herself. Madrigo had a history of strong alchemists, primarily focused on metallurgy, but with enough biomancers in the family to make her transformation very plausible.
The stories disagree on whether her son was her first test subject, a simultaneous effort, or later recruited to her cause once she was leading a rebellion and needed an ally. Regardless, even though her son is just as much of a Mantlewray as her, he is not called by his familial name, Jubalcain Monastus Mantlewray. Instead he is called The Lech, or sometimes The Son of the Squid.
Why did Lady Mantlewray become the leviathan?
To fight the merfolk in their own element, perhaps, and safeguard Bospero harbor from their drills, nets, and horrible dolphins.
Another story claims that she did it to flee an abusive marriage. (It is agreed that her own estate was among the first that she destroyed.)
And yet another story claims that she simply desired power. There are no supporting facts required for this explanation--human nature has proved it to be true countless times.
These theories are not mutually exclusive, and her true rationale is probably not limited to a single motivator.
Still, is it difficult to see the brutal remains of her violence and think them to be products of a subtle mind. Everywhere in the city, you can see places where the stone is lashed to the foundation by rasping tentacles. Certain spires are still bent and rusted by her terrible exhalations. And although the birth defects have declined, it is not rare to see an elder whose body has been bent by her cruel poisons.
The only places that do not bear her scars are the Holy City of Coramont (because she did not dare), and the Golden Road (because she could not).
A Sidebar: The Golden Road
The Golden Road is a bridge that traverses the Bosperian Bay, connecting Bospero with its sister city of Marinda. The bridge is 36 miles long, and is usually crossed in three days. The bridge is studded with fortifications dating back to the Road War, when both Marinda and Bospero competed for control of the Golden Road. It was a long, bitter, slow conflict that Bospero ultimately won.
The Golden Road is built from adamantine, and shares other similarities with the Bastion of Medurak (a dam) and the Forbiddance (a wall). Bospero has mixed feelings about the Golden Road. It connects them to the lands to the north, but it has also allowed foreign armies to swiftly march into the city. They are proud of it because they control it, but they are frustrated that they cannot even chip the least piece of its structure.
End of Sidebar
During the rebellion she was the Traitorous Abomination. When she was crowned, she was Lady Mantlewray again. And now that she has loosened her grip on the throne and the city, she has regressed into the Mantlewray, well on her way to becoming a beast again.
And as the Mantlewray becomes more and more withdrawn, she concerns herself with less and less of the world. There are few alive who have heard her speak, and certainly no one living remembers her tearful confessions in Coramont, her supplications at the feet of the Prophetessa (May She Live Again), and the forgiveness that she received.
In fact, the only thing that seems to concern the Mantlewray these days is the potency and punctuality of her drugs, a task that has only become more challenging over the years as both the Mantlewray and her son has grown larger over the decades.
But while the Mantlewray is withdrawing from the city that she once ruled, her son leans into it more with every passing year. For a while, he was fascinated with brewing, and ran a brewery for years, producing several quality lagers. Everyone agrees that the accident wasn't his fault.
Then it was cigars. Then it was horses. Then it was a distillery. Then he went to work on his shell, adding new chambers, bolstering his seams with bronze, and spinning his natural spines into monstrous spires and involutions. Then it was horses again.
For a while, he attended plays--his monstrous face peering over the roof of the theater, the light lessened by the shadows cast by the cyclopean parapets of his shell. He had no hands to clap with, but he voiced his approval by stamping his dozens of feet in the street outside, the sound of boulders falling. He brought many gifts for his favorite actresses.
And then it was girls. Perhaps it was something like a delayed puberty, an artifact of the many contortions his mother inflicted on his biology. Or perhaps he finally located his genitals within the cavernous carapace of his. Regardless, he threw himself into this newest mania with an appetite exceeding even his own previous frenzies.
He attempted the more typical methods of courtship, but after the predictable failure, he moved on to more transactional enterprises. Soon he was showing up to the plays with a nest of strumpets among the crenellations of his shell. He had gold aplenty, his mother's gold, dug up from whatever secret reef she had buried it during her regency.
The Lech visited the city even more, then. You could hear the booming gurgle as he laughed from the harbor, as he showed another girl how to use his mother's enormous harbor-bong. You could see him in the Grocer's Harbor, his gracile oral tentacles loading furniture into his freshly expanded shell, the prostitutes carrying off another chaise lounge to furnish some interior boudoir.
Artisans were brought in. His shell was caulked and sealed. He had airtight compartments, now. He could bring his girls down with him. He was too heavy to swim, but his crab legs could carry that castle through all the Bosperian depths.
He thought of himself as a clam, and the girls as his pearls.
Down in the bottom of the bay, where the watery sun above was paler than the moon, his girls would massage his aching mantle, and they would ask him about his childhood as a human. Did he remember his hands? Did he remember what is was like to kiss?
And in the face of these questions, he could only lie.
How to Use This in Your Game
I hope that you think that Lady Mantlewray and her son are as interesting as I do. They are certainly powerful, if you were to plop them down in your campaign world.
Lady Mantlewray's brain contains a wealth of potent knowledge. If you could find some way to leverage it, a piece of that trove could be yours. You could get a fortune of gold, or turn yourself into a kaiju of your own design. As an enemy, Lady Mantlewray is about as dangerous as any other 60,000 ton monster, so be careful before you tamper with her drug supply.
What does she want? An escape from her melancholy perhaps, or a remnant of her earlier days. Perhaps she wants her humanity back. Regardless, there are plenty of people in town who can answer this for you. Her son, perhaps, or even the Prophetessa (May She Live Again).
Her son might yield easier leverage, but perhaps in a riskier way. He is not dumb, although he may be a bit naive. And unlike his mother, the players will probably have no trouble thinking of ways to entice him.
There's also a great deal of interested parties. Many people would like to see the two monsters dead. The Marilanth Petal would like to be free of this responsibility, even though it would degrade their special status. (They've tried poisoning her; they don't recommend it.) The death of the monsters would also create a tremendous glut of drugs, unless the Marilanth Petal can keep a lid on things and enforce a certain level of stockpiling.
The merfolk would like to see the Mantlewray destroyed. Without her presence, the Bosperian ships are vulnerable again.
And even pieces of the monsters are valuable. There are many alchemists and biomancers who would pay handily for even a piece of the creatures: the Stewer's Guild, the Transmetallic Alchemists, Grandfather Oshregaal, etc.
Even the pieces are valuable. The players could be hired to steal a vulnerable cache of drugs (at the risk of incurring the Mantlewray's wrath). They could be hired to steal a velvet ooze from inside the Lech. You can even use the Lech as a questgiver (whose identity isn't immediately disclosed), as there are certainly many things that he would want to acquire, and many of which require a bit of legally ambiguous footwork.